ATHENS, Ala. — Police say a man killed his 10-year-old son and his sleeping 84-year-old mother before turning the gun on himself and taking his own life in northern Alabama.

Athens police said in a statement that William “Billy” Christopher shot 10-year-old Chevy Christopher and 84-year-old Betty Sue Christopher on Saturday in Athens.

Athens police Capt. Trevor Harris said in a statement that investigators were working to find a motive for the crimes.

Harris said the child had spent the night with his father and grandmother on Friday. The next morning, the boy’s mother couldn’t reach them by phone or get an answer at the door, so she contacted a relative with a key who found the three bodies.